JP4137784B2 - Solar power generator control system - Google Patents

Description

  The present invention includes a solar power generation means for generating electricity by sunlight, a power storage means for storing the power generated by the solar power generation means, charging the power storage means with the power generated by the solar power generation means, and The present invention relates to a photovoltaic power generation apparatus control system comprising charge / discharge control means for controlling discharge to a load by means.

  As a conventional solar power generation device control system, for example, in the daytime, power is generated by a solar cell, and an inverter is used as an alternating current to supply power to the optical terminal device, and the storage battery is charged, and surplus power is sold to an electric power company. On the other hand, a power system for optical terminal devices that uses commercial power at night and is operated with stored battery power during nighttime power outages or during daytime power outages when solar power generation cannot be performed has been proposed. (For example, refer to Patent Document 1).

  Moreover, it has a private power generation power supply part provided with a solar battery and a storage battery, the solar battery generates power in response to sunlight, supplies power to the optical communication terminal device via the load power supply part, and supplies power to the storage battery. The storage battery charges the power supplied from the commercial power supplement supply unit and the solar cell, and supplies the charging power to the load power supply unit. The commercial power supplement supply unit receives the AC current received from the commercial power source. The power supply control unit converts the charging power amount of the storage battery and the supplementary power supplied by the commercial power supplementary supply unit using sensor information such as an ammeter by converting the direct current to the storage battery and the load power supply unit. A power supply system for controlling power supply has been proposed (see, for example, Patent Document 2).

  Furthermore, in an ac-end commercial switching solar cell power supply system that uses a storage battery, the amount of electricity generated by the solar cell is counted by an integrating wattmeter, and the amount of discharge from the storage battery is determined according to the amount of power generated per day. A storage battery control method for a solar battery power system has also been proposed in which the battery is protected and efficiently operated by discharging to 50% of the storage battery capacity when approaching a charged state (for example, Patent Documents). 3).

Furthermore, the DC power of solar cells and storage batteries is reversely converted to AC power by interconnection operation and self-sustained operation, and power is supplied to the load, and the AC power of the power system is forward-converted to DC power for charging by charging operation. The control device of the power converter to be supplied has a means for discriminating between daytime and nighttime from the magnitude of the solar battery voltage, a means for monitoring the voltage of the storage battery, and the voltage of the storage battery is close to the overdischarge voltage during the daytime when the system is normal The power conversion device is controlled to be charged every time the discharge limit voltage is set to, and at night when the system is normal, the power conversion device is turned on every time the storage battery voltage drops to the lower limit voltage of the charge state higher than the discharge limit voltage. A solar power generation device provided with a means for controlling charging operation has been proposed (see, for example, Patent Document 4).
JP-A-8-163793 (first page, FIG. 1) Japanese Patent Laid-Open No. 10-285825 (first page, FIG. 1) JP-A-7-38130 (first page, FIG. 1) Japanese Unexamined Patent Publication No. 2001-224142 (first page, FIG. 1)

  However, in the conventional example described in Patent Document 1, it is a solar power generation system that charges a storage battery and supplies power to a load with power generated by the solar battery. Since the system is controlled by the relationship with the load capacity, the solar battery power is used for supplementary charging of the storage battery during the daytime, and only the commercial power supply is used at night, and the storage battery cannot be used effectively. There is a problem.

  Moreover, in the conventional example described in Patent Document 2, since the power necessary for the power failure of the commercial power supply is sufficiently stored in the storage battery, it is a system that can effectively use the storage battery. When fully charged, the battery must be discharged to protect the battery, which can lead to excessive battery charge / discharge cycles, and the unresolved issue of not considering the impact on the life of the battery. is there.

  Furthermore, in the conventional example described in Patent Document 3, a solar battery power supply system storage battery control that extends before the depth of discharge of the storage battery becomes deep until it reaches a state that adversely affects the life of the storage battery, thereby extending the life of the storage battery. However, this is because the storage battery is charged by repeated charge and discharge by discharging a certain amount of power of the storage battery and slightly increasing the charge amount from the discharge amount to the storage battery with reduced power. However, it is a stand-alone system that does not have a grid connection function with a commercial power source, and changes in the amount of power generated from solar cells throughout the year are not taken into account. There is an unsolved problem that there is a case where it is likely to be in a charged state and there is a state where it takes a very long time to charge the storage battery.

Furthermore, in the conventional example described in Patent Document 4, during the daytime when the system is normal, the power converter is put into charge operation every time the voltage of the storage battery decreases to the discharge limit voltage set near the overdischarge voltage. When the power is normal, the power converter is controlled to charge every time the storage battery voltage drops to the lower limit voltage of the charging state that is higher than the discharge limit voltage. There is an unsolved problem of giving
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and charging the storage battery with electric power obtained from the solar battery and its storage battery power can be utilized and expected It aims at providing the photovoltaic power generation device control system which can ensure a lifetime.

In order to achieve the above object, a solar power generation apparatus control system according to claim 1 includes a solar power generation unit that generates power by sunlight, a power storage unit that stores electric power generated by the solar power generation unit, and the solar power generation unit. In the solar power generation device control system comprising the charge / discharge control means for charging the power storage means with the power generated by the power generation means and controlling the discharge from the power storage means to the load, the charge / discharge control means includes the A charge control means for charging the power storage means within a predetermined time in a time zone in which the power consumption of the load is low, and a discharge for discharging the load from the power storage means to the load outside the charging time of the charge control means and control means, and the over-charge state detecting means for detecting a manner that leads to overcharge state by the charge control unit, the number of detected overcharged state detected by the overcharge detecting means is less than a predetermined number The discharge control means reduces the depth of discharge of the power storage means, and the discharge control means maintains the discharge depth of the power storage means when the number of overcharge state detections is within a predetermined number range. Discharge depth determining means for deepening the discharge depth of the power storage means by the discharge control means when the number of state detections exceeds a predetermined number is provided.

In addition, the solar power generation device control system according to claim 2 includes a solar power generation unit that generates power using sunlight, a power storage unit that stores electric power generated by the solar power generation unit, and electric power generated by the solar power generation unit. And charging / discharging control means for controlling discharge from the power storage means to the load, and the charge / discharge control means is configured such that the power consumption of the load is A charge control means for charging the power storage means within a predetermined time in a small time zone; a discharge control means for discharging the load from the power storage means to the load outside the charge time at the charge control means; and the charging Overcharge state detection means for detecting the mode leading to the overcharge state by the control means, and the charging time from the predetermined discharge depth detected by the overcharge state detection means to the overcharge state is set and charged. The depth of discharge of the power storage means is maintained when it is time, the depth of discharge of the power storage means is deepened when the charging time is shorter than a set charging time, and the power storage means is set when the charging time is longer than the set charging time. And a discharge depth determining means for reducing the depth of discharge .

Furthermore, photovoltaic power generator control system according to 請 Motomeko 3 is the invention according to claim 1 or 2, wherein the charging control means, power generation by the solar power generation means as a time zone less power consumption of the load It is characterized in that it is configured to set a predetermined time between possible early morning and morning .

According to a fourth aspect of the present invention, there is provided a photovoltaic power generation apparatus control system according to any one of the first to third aspects, wherein the discharging means is configured to increase or decrease a discharging power amount of the power storage means depending on a charging power amount. It is characterized by having.

According to the invention of claim 1, by changing the depth of discharge depending on whether the number of overcharged state detections is less than a predetermined number, within a predetermined number range, or exceeding a predetermined number, The depth of discharge is automatically controlled in accordance with the amount of power generated by the photovoltaic power generation means, and the effect that the life of the battery can be increased by maintaining the amount of power stored in the power storage means in an appropriate state .

According to the invention of claim 2, depending on whether the charging time from the predetermined depth of discharge to the overcharge state is less than the set time, within the set time range, or exceeds the set time By changing the depth of discharge, it is possible to automatically control the depth of discharge according to the amount of power generated by the solar power generation means, to maintain the amount of power stored in the power storage means in an appropriate state, and to extend the service life. An effect is obtained.

Furthermore, according to the invention according to claim 3, in the charging control unit, a period of low power usage of the load, 10:00 in the morning from early morning, for example, about 6:00 possible power generation in solar power unit by setting the degree, time zone less power consumption of the load, Ru effect is obtained that the power storage means can be reliably charged.

Still further, according to the invention of claim 4 , the discharging means for discharging the amount of electricity stored in the electricity storage means is configured to increase or decrease the amount of electric power discharged from the electricity storage means depending on the amount of charging electric power, leading to overcharging. By controlling the amount of discharge electric power according to the mode, an effect that the depth of discharge can be set according to the mode leading to overcharge is obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a solar power generation apparatus control system, and this solar power generation apparatus control system 1 is a solar power generation means for generating power by sunlight. As a solar cell 2, a DC power output from the solar cell 2, an inverter 3 that converts this into AC power, a storage battery 4 that is charged by the solar cell 2, and a commercial power source that supplies commercial AC 5, an important load 6 to which electric power is supplied from the inverter 3 and the commercial power source 5, and a solar cell control device 7 that controls system switching of the solar cell 2, the inverter 3, and the storage battery 4.

  Here, the solar cell 2 has a configuration in which nine battery units BU1 to BU9 having a configuration in which 13 polycrystalline silicon solar cells are connected in series are connected in parallel, and the total DC output is about 19 kW. Is set. A series circuit of string control selection switches SW1 to SW9 and diodes D1 to D9 is connected to the output side of each battery unit BU1 to BU9, and the cathodes of the diodes D1 to D9 are connected to each other at one end of the open / close switch SW0. The other end of the open / close switch SW0 is directly connected to the open / close switch SWI provided on the input side of the inverter 3.

  The inverter 3 is connected to the commercial power source 5 to supply power to the important load 6. The inverter 3 is connected to the commercial power source 5. The independent output terminal 3 b is disconnected from the commercial power source 5 to supply power to the important load 6 by independent operation. The interconnection output terminal 3a is connected to the commercial power source 5, the connection point thereof is one fixed side contact ta of the changeover switch SWL, and the self-sustained operation output terminal 3b is the other fixed side contact tb of the changeover switch SWL. The movable contact tc of the changeover switch SWL is connected to the important load 6.

In the storage battery 4, 138 clad (CS) cells of 2V are connected in series, the nominal voltage is set to 276V, the overvoltage of each cell is set to 2.4V, and the overall overvoltage is set to 331.2V. The entire voltage is set to 1.8V for each cell and 248.4V for the whole. The storage battery 4 is connected to a connection point between the open / close switch SW0 of the solar battery 2 and the inverter 3 via the open / close switch SWB.
The important load 6 is a facsimile, a weather terminal, a copier, a printer, a monitor, an emergency lighting device, etc. installed in a disaster prevention center that needs to be supplied with AC power even when the commercial power supply 5 is in a power failure state in the event of a disaster. The uninterruptible power supply 8 corresponding to the instantaneous power failure at the time of switching of the change-over switch SWL is disposed on the input side thereof.

  The solar cell controller 7 includes a voltmeter VM1 and an ammeter AM1 that detect an output voltage and an output current output from the solar cell 2, a voltmeter VM2 and an ammeter AM2 that detect an output voltage and a charge / discharge current of the storage battery 4, and The detection signals from the multimeters MM1 and MM2 that simultaneously measure the current, voltage, and power of the interconnection output and the independent output of the inverter 3 are input, and based on these, the operation mode is set to the interconnection operation mode, and the storage battery 4 is periodically set. A charging mode for charging the battery, a discharging mode for discharging the storage battery 4, and a self-sustained operation mode when the commercial power source 5 is in the event of a power failure, and opening / closing control of the open / close switches SW0, SWB, SWI according to the selected operation mode and the inverter 3 The switching between the interconnection operation and the independent operation and the switching of the changeover switch SWL are controlled.

  The solar cell control device 7 executes the control process shown in FIG. In this control process, first, in step S1, it is determined whether or not it is a preset charging start time. If it is the charging start time, the process proceeds to step S2 and the open / close switch SWI on the input side of the inverter 3 is set. Then, the process proceeds to step S3 to stop the operation of the inverter 3, and then the process proceeds to step S4 to turn on both the open / close switch SWB of the storage battery 4 and the open / close switch SW0 of the battery units BU1 to BU9. At the same time, after the movable contact tc of the changeover switch SWL for the important load 6 is switched to the fixed contact ta on the commercial power source 6 side, the process proceeds to step S5.

  In this step S5, a command to start string control is output to the open / close switches SW1 to SW9 of the battery units BU1 to BU9, and then the process proceeds to step S6, where the open / close switch SWB is turned on and detected by the ammeter AM2. The charging current is read, and it is determined whether the storage battery capacity VB1 estimated based on the charging current is equal to or greater than a preset overcharge setting value VOs (storage battery capacity 400Ah). In addition, since the relationship between the rechargeable battery capacity and the storage battery voltage is not a proportional appraisal, it is difficult to manage the storage battery capacity with the voltage. Therefore, in the present invention, the charge / discharge power amount to the storage battery 4 is detected using the ammeter AM2. Thus, the storage battery capacity is estimated and managed.

If it is determined in this step S6 that VB1> VOs, the process proceeds to step S7 to determine whether or not the charging end time has been reached. If it is determined in step S7 that the charging end time has not been reached, the process returns to step S6 to continue charging.
If it is determined in step S6 that VB1> VOs, the process proceeds to step S8, the overcharge arrival count N is incremented, and then the process proceeds to step S9. Further, when it is determined in step S7 that the charging end time has been reached, the process proceeds to step S9.

  In step S9, it is determined whether it is the end of the day when the dischargeable electric energy VUs for changing the discharge depth of the storage battery is reviewed, for example, the end of the month. If not the end of the month, the process proceeds to step S15. If it is determined in step S9 that it is the end of the month, the process proceeds to step S10, where it is determined whether or not the number N of overcharge arrivals for one month is smaller than the lower limit value Ns1, and if it is determined that it is small Shifts to step S11, increases the dischargeable energy setting value VUs by ΔV, shifts to step S14, and clears the overcharge arrival count N to “0”.

When the overcharge reached the number N is determined to be larger than the lower limit value Ns1 in step S10, proceeds to over-charging reaches the number N is determined whether less than the upper limit value Ns2 in step S12, a small If it is determined, the process proceeds to step S14, and the overcharge arrival count N is cleared to "0".
In step S12, it is determined whether or not the overcharge arrival frequency N is smaller than the upper limit value Ns2. If it is determined that the overcharge arrival number N is larger, the process proceeds to step S13, and the dischargeable energy setting value VUs is decreased by ΔV. The process proceeds to step S14, and the overcharge arrival count N is cleared to "0".

  As the lower limit value Ns1 and the upper limit value Ns2, for example, by setting such as 2 times / month and 6 times / month, when the overcharge arrival number N does not reach twice, the discharge depth is too deep. Therefore, if the dischargeable energy setting value VUs is increased by ΔV to reduce the discharge depth, and the overcharge arrival count N exceeds 6, the discharge depth is too shallow. Therefore, the discharge depth setting value VUs can be reduced by ΔV to increase the discharge depth.

When the overcharge arrival count N is cleared to “0” in step S14, the process proceeds to step S15 to output a string control stop command, and the process proceeds to step S16 to open / close the switch SWB. The control to turn on is performed, the charging of the storage battery 4 is finished, and the electric power generated by the solar battery 2 is supplied to the inverter 3.
When the process of step S16 ends, the process proceeds to step S17. In this step S17, it is determined whether or not it is a preset discharge start time. If it is not the discharge start time, the process proceeds to step S18 and the solar cell 2 After the generated power is converted into AC power by the inverter 3 and connected to the important load 6 together with the AC power from the commercial power source 5, the process returns to Step S <b> 1, and when it is the discharge start time, the process proceeds to Step S <b> 19. Then, after performing the discharge process of FIG. 3 described later, the process returns to step S1.

  Moreover, when the determination result of said step S1 is not a charge start time, it transfers to step S21, it is determined whether the commercial power source 5 is a power failure state, and when it is a power failure state, it transfers to step S22, The self-sustained operation process of converting the electric power of the solar battery 2 or the rechargeable battery 4 into alternating current by the inverter 3 and supplying it to the important load 6 via the changeover switch SWL is terminated, and the process is terminated. Migrate to

  As shown in FIG. 3, the discharge process in step S19 is first performed in step S31 by turning off the open / close switch SW0 of the solar cell 2 and the open / close switch SWB of the storage battery 4 and the input side open / close switch of the inverter 3. Both of the SWIs are controlled to be in the ON state, then the process proceeds to step S32, the inverter 3 is set in the self-sustained operation state, and then the process proceeds to step S33 to read the self-supporting output voltage of the inverter 3 detected by the multimeter MM2. It is determined whether or not there is an output voltage. If there is no self-sustained output voltage, the process waits until there is a self-sustained output voltage. If there is a self-sustained output voltage, the process proceeds to step S34.

In this step 34, the movable contact tc of the changeover switch SWL for the important load 6 is controlled to be switched to the fixed contact tb side which is the self-sustained output side of the inverter 3, and the process proceeds to step S35, where the discharge current detected by the ammeter AM2 is obtained. It is determined whether the storage battery capacity VB1 of the storage battery 4 estimated based on this is equal to or larger than the overcharge set value VOs. If equal to or larger, that is, if the overcharge setting has been reached during charging, the process proceeds to step S36. The discharge is performed until the storage battery capacity VB1 reaches the dischargeable electric energy set value VUs. When discharging is performed until the storage battery capacity VB1 reaches the dischargeable power amount set value VUs in step S36, the process proceeds to step S39. Since the resistance value of the important load 6 is known and does not change, the discharge amount per unit time is constant regardless of the storage battery capacity. Therefore, at the time of discharging after the storage battery capacity VB1 reaches the overcharge set amount VOs, the dischargeable power amount set value VUs is selected so that the dischargeable power amount set value VUs is discharged by the next charge start time. .

  If it is determined in step S35 that the storage battery capacity VB1 has not reached the overcharge set value VOs, the process proceeds to step S37, and the discharge amount set value Vds per time is calculated and set. This discharge amount set value Vds can be set as ½ of the charge amount as an example. By discharging 1/2 of the charged amount, the storage battery capacity VB1 reaches the overcharge set value VOs by repeating charging and discharging several times.

  When the discharge amount set value Vds is set in step S37, the process proceeds to step S38, and discharge control is performed. This discharge control is performed by estimating the discharge amount Vd based on the current value detected by the ammeter AM2 and determining whether the estimated discharge amount Vd has reached the discharge amount set value Vds. When the discharge amount Vd reaches the discharge amount set value Vds, the process proceeds to step S39.

In this step S39, the movable contact tc of the changeover switch SWL for the important load 6 is controlled to be switched to the fixed contact ta side on the inverter 3 and the commercial power source 5 side, and then the process proceeds to step S40, where the input side on / off switch of the inverter 3 is switched. The SWI is turned off, and then the process proceeds to step S41 to stop the operation of the inverter 3 and returns to the above-described process of FIG.
2 and 3, the processes in steps S1 to S8 and S15 to S17 correspond to the charge control means, the process in step S6 corresponds to the overcharge state detection means, and the processes in steps S9 to S14 are discharged. Corresponds to the depth determination means.

Next, the operation of the above embodiment will be described.
First, regardless of the season, the charging time of the storage battery 4 by the solar battery 2 is from 6:00 am, when the power consumption of the important load 6 is low and after solar power generation, as shown in FIG. Set 4 hours until 10am. On the other hand, the discharge start time of the storage battery 4 is set to a time when the power consumption of the important load 6 is the smallest, for example, midnight. Here, the discharge start time is set so that the discharge from the overcharge voltage to the maximum discharge depth can be performed when the discharge depth of the storage battery 4 is set to the maximum.

  If it is assumed that the discharge process ends in the early morning of the month and is before the charge start time, in this state, the control process of FIG. 2 proceeds from step S1 to step S20, and the commercial power supply 5 is normal. If it is, since it will transfer to step S17 and the charge start time has passed, it will transfer to step S18 and an interconnection operation process will be performed. At this time, the open / close switch SWB of the storage battery 4 is controlled to be in an off state, and in the state where there is almost no power generation amount in the solar battery 2 before sunrise, this is detected by the voltmeter VM1 and the ammeter AM1. 3 and the input side open / close switch SWI are both controlled to be in an OFF state, the operation of the inverter 3 is stopped, and the AC power of the commercial power supply 5 is supplied to the important load 6 via the changeover switch SWL. Printers, facsimiles, etc. are ready for use.

  In this state, when the solar cell 2 is irradiated with sunlight at the sunrise time, the voltmeter VA1 and the ammeter AM1 detect the electric power generated by the battery units BU1 to BU9 constituting the solar cell 2. Then, the input side switch SWI of the inverter 3 is turned on, the inverter 3 is controlled to be connected, and AC power is output from the inverter 3 so that the connected operation with the AC power from the commercial power supply 5 is performed. Done.

  In this interconnection operation state, when the charging start time comes at 6:00 am, the input side open / close switch SWI of the inverter 3 is turned off and the inverter 3 is controlled to stop by the control processing of FIG. S2, S3) and the open / close switch SW0 of the solar battery 2 continues to be in the on state, and the open / close switch SWB of the storage battery 4 is switched to the on state, whereby the generated power of the solar battery 2 is supplied to the storage battery 4 4 starts charging. On the other hand, since the changeover switch SWL of the important load 6 maintains the state of switching on the commercial power supply 5 side, the commercial load is supplied to the important load 6 from the AC power supply 5 and is continuously used by a weather terminal, copy, facsimile, etc. It is possible.

In this charged state of the storage battery 4, the open / close switches SW1 to SW9 connected to the output sides of the battery units BU1 to BU9 constituting the solar battery 2 are string controlled so that the amount of charging power supplied to the storage battery 4 is in an appropriate state. It is controlled (step S5).
For this reason, the storage battery capacity VB1 of the storage battery 4 detected by the voltmeter VM2 increases with time as shown in FIG. When the storage battery capacity VB1 becomes equal to or greater than the preset overcharge set value VOs, the overcharge arrival count N is incremented (step S7), but when the storage battery voltage VB1 does not reach the overcharge set value VOs, 10 am It is determined whether or not the charging end time set at the time has come, and when it is not the charging end time, the charging state is continued, and when the charging end time is reached, the charging process is terminated without incrementing the overcharge arrival number N, Transition to interconnected operation processing.

  Thereafter, when the discharge start time at midnight is reached, the discharge process of FIG. 3 is started, and both the input side open / close switch SWI of the inverter 3 and the open / close switch SWB of the storage battery 4 are controlled to be on and the inverter 3 is independent. When the operation state is controlled so that a self-sustained output voltage can be obtained from the inverter 3, the changeover switch SWL of the important load 6 is switched from the commercial power source 5 side to the self-sustained output side of the inverter 3, and the discharge power of the storage battery 4 is discharged. Is supplied to the important load 6 and the storage battery 4 is discharged. At this time, since the resistance of the important load 6 is constant, the storage battery capacity VB1 decreases with a constant slope as shown in FIG. 5, and the discharge amount set value Vds is discharged or the dischargeable electric energy When the set value VUs is discharged, the discharge process of the storage battery 4 is terminated, and the power supply from the commercial power source 5 is started.

By the way, in winter, the amount of sunlight is small and the amount of power generated by the solar cell 2 is small. In summer, the amount of sunlight is large and the amount of power generated by the solar cell 2 is large. It will vary greatly depending on the season. For this reason, for example, the dischargeable electric energy set value VUs set at the end of May Assuming that the charging / discharging process of the storage battery 4 was performed as shown by the solid line in FIG. 5 in June during the rainy season, the amount of sunshine increased simultaneously with the end of the rainy season in July. When the amount of power generated by the solar cell 2 also increases, the overcharge arrival count N counted in the processing of FIG. 2 until the end of the rainy season is substantially equal to June, but the overcharge arrival count N after the end of the rainy season. When the overcharge arrival count N at the end of July exceeds, for example, the upper limit value Ns2, the dischargeable energy setting value VUs By adding a predetermined value ΔV to the current value. The dischargeable power amount set value VUs1 is changed, and the discharge amount of the storage battery 4 increases, and the discharge depth becomes deeper as shown by the broken line in FIG.

Furthermore, since the amount of sunshine increases further in August, the discharge depth becomes the maximum in one year by adding a predetermined value ΔV based on the number of overload arrivals in the same manner.
After that, in September, the overcharge arrival frequency N falls within the range between the lower limit value Ns1 and the upper limit value Ns2, and the dischargeable energy setting value VUs. However, if the number of overcharges N decreases due to a decrease in the amount of sunlight and the amount of power generated by the solar cell 2 thereafter, the dischargeable power amount set value VUs is accordingly increased. Decreases and the depth of discharge becomes shallower.

Thus, according to the above-described embodiment, by detecting the overcharge arrival frequency N, it is possible to control the depth of discharge and maintain the charged amount after charging the storage battery 4 in a high state regardless of the season, always be able to be fully charged, it is possible to drive reliably important load 6 even if the commercial power source 5 is a power failure in the event of a disaster, so setting the depth of discharge based on the overcharge reached number N The storage battery capacity can be accurately managed. Incidentally, when managing the storage battery capacity with the storage battery voltage, if the discharge current from the storage battery is large, the storage battery voltage is also likely to drop, and the remaining storage battery capacity can be easily estimated from the storage battery voltage. In order to be able to supply power to the emergency safety load during a long power outage of about 24 hours, the discharge current tends to decrease, and the storage battery voltage and the storage battery capacity are not proportional to each other, and the storage battery capacity is based on the storage battery voltage. It becomes difficult to manage.

Moreover, since the charging / discharging of the storage battery is controlled by the cycle operation determined every day, it is easy to make a plan for the expected life of the storage battery, and the discharge amount is controlled according to the charge amount of the storage battery 4, so the storage battery Can be used effectively to reduce the amount of commercial power used.
Moreover, since the depth of discharge is set based on the number N of overcharge arrivals, the average discharge depth of the storage battery becomes shallow, and the expected life of the storage battery can be prolonged.
In addition, in the said embodiment, although the case where the depth of discharge was set based on the overcharge arrival frequency N was demonstrated , it is not limited to this, The discharge amount of a storage battery is set based on the overcharge arrival frequency N Then, the discharge power amount at this time may be detected by a detector, and the discharge may be stopped when the discharge power amount of the storage battery 4 reaches the set value discharge amount.

  Moreover, in the said embodiment, although the case where the charge state of the storage battery 4 was detected by detecting the overcharge arrival frequency N was demonstrated, it is not limited to this, As shown in FIG. Charging is started when the capacity VB1 is less than the set value Vs, and the overcharge arrival time Td until the storage battery capacity VB1 reaches the overcharge set value VOs from the set value Vs is measured. When the charge arrival time Td is greater than or equal to the preset upper limit value Td1, the current discharge depth is reduced (charging pattern 1), and when the charge arrival time Td is within the upper limit value Td1 and lower limit value Td2 as in the spring or fall The current discharge depth is maintained (charge pattern 2), and the current discharge depth is deepened (charge pattern 3) when it is less than the lower limit value Td2 as in summer, so that the same effect as in the above embodiment is obtained. It is possible to obtain.

The relationship between the charge power amount and the discharge power amount and the overcharge arrival frequency when the dischargeable power amount setting value is changed in this way will be described with reference to FIG. 6A shows a case where the discharge depth is increased by setting the dischargeable power amount setting to a large value VUs1, and FIG. 6B shows a case where the discharge depth is made shallow by setting the dischargeable power amount setting a small value VUs2. As in FIG. 5, the discharge electric energy per time is half of the charge electric energy when it does not reach the overcharge set value, and when the overcharge set value is reached, all the dischargeable electric energy set values are discharged. assuming that, in FIG. 6 and (a) (b) is completely discharged electric power amount and the charging electric energy the same, overcharge reached number (a) is one, it is twice (b). Accordingly, if the charge power amount and the discharge power amount are the same, the number of overcharge arrivals increases, and the dischargeable power amount set value VUs2 is reduced as shown in (b), and the charge / discharge is repeated with a shallow discharge depth. Can secure the battery life.

  Furthermore, in the said embodiment, although the overcharge arrival frequency N demonstrated the case where the present discharge state is maintained when it exists in the range of lower limit Ns1 and upper limit Ns2, it is not limited to this, The current discharge state is maintained when the overcharge arrival count N matches the set value Ns, the discharge time is shortened when it is less than the set value Ns, and the discharge time is lengthened when it exceeds the set value Ns. You may do it.

Furthermore, in the above embodiment, the case where the charging time of the storage battery 4 is set to 4 hours has been described. However, the present invention is not limited to this, and the charging time can be arbitrarily set and the charging start time is set. The charging start time may be set differently in summer and winter.
Furthermore, in the above embodiment, the case where the discharge condition is set in units of one month has been described. However, the present invention is not limited to this, and the discharge condition can be set every arbitrary period.
Moreover, in the said embodiment, although the case where the electrical equipment required at the time of a disaster occurrence as an important load was applied was demonstrated, it is not limited to this, For the equipment which needs to be driven at the time of a power failure of the commercial power source 4 The present invention can be applied.

It is a block diagram which shows one Embodiment of this invention. It is a flowchart which shows an example of the control processing procedure performed with the solar cell control apparatus of FIG. It is a flowchart which shows the specific example of the discharge processing procedure of FIG. It is a time chart which shows the charge / discharge cycle of 1 day with which it uses for description of operation | movement of this invention. It is a time chart which shows the charging / discharging state of a storage battery. It is a time chart which shows the charging / discharging state of the storage battery in a different discharge depth. It is a figure which shows the charging time of a storage battery.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Solar power generation device control system, 2 ... Solar cell, UB1-UP9 ... Battery unit, SW0-SW9 ... Open / close switch, 3 ... Inverter, SWI ... Open / close switch, 4 ... Storage battery, SWB ... Open / close switch, VM1, VM2 ... Voltmeter, 5 ... Commercial power supply, 6 ... Important load, SWL ... Changeover switch, 7 ... Solar cell control device

Claims (4)

Solar power generation means for generating power by sunlight, power storage means for storing the power generated by the solar power generation means, charging the power storage means with the power generated by the solar power generation means, and from the power storage means to the load In a solar power generation device control system comprising a charge / discharge control means for controlling the discharge of
The charge / discharge control means includes: a charge control means for charging the power storage means within a predetermined time in a time zone where the power consumption of the load is low; and the charge control means from the power storage means outside the charge time in the charge control means. a discharge control means for discharging to the load, and the overcharged state detecting means for detecting a manner that leads to overcharge state by the charge control unit, the number of detected overcharged state detected by the overcharge detection means a predetermined The discharge control means makes the depth of discharge of the power storage means shallow when the discharge control means is less than a number, and maintains the discharge depth of the power storage means by the discharge control means when the number of overcharge detections is within a predetermined number range. , photovoltaic instrumentation, characterized in that the number of detected overcharge state has a depth of discharge determining means for deeper depth of discharge of the accumulator unit by said discharge control means when it exceeds the predetermined number Control system. Solar power generation means for generating power by sunlight, power storage means for storing the power generated by the solar power generation means, charging the power storage means with the power generated by the solar power generation means, and from the power storage means to the load In a solar power generation device control system comprising a charge / discharge control means for controlling the discharge of
The charge / discharge control means includes: a charge control means for charging the power storage means within a predetermined time in a time zone where the power consumption of the load is low; and the charge control means from the power storage means outside the charge time in the charge control means. A discharge control means for discharging the load; an overcharge state detection means for detecting a charging time from a predetermined depth of discharge to an overcharge state by the charge control means; and a predetermined value detected by the overcharge state detection means When the charging time from the depth of discharge to the overcharge state is a set charging time, the depth of discharge of the power storage means is maintained, and when the charging time is shorter than the set charging time, the depth of discharge of the power storage means is increased. A photovoltaic power generation apparatus control system comprising: a discharge depth determining means for reducing a discharge depth of the power storage means when the charging time is longer than a set charging time . The charging control means is configured to set a predetermined time in the morning from early morning in which the power generation by the solar power generation means is possible as a time zone when the amount of power used by the load is small. The solar power generation device control system according to 1 or 2 . It said discharge means, photovoltaic power generator control system according to any one of claims 1 to 3, characterized in that it is configured to increase or decrease the charging electric energy discharged power amount of the power storage means.

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